User interface for a portion of a display screen



The FIGURE is a front view of a user interface for a portion of a display screen showing our new design.

The disclaimed broken line rectangular element partially superimposed below the claimed design in the Figure is for illustrative purposes to show the translucent appearance, and forms no part of the claimed design. The broken line showing of various regions and the unshaded areas there within form no part of the claimed design. The broken line showing of the display screen is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 